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981.
Cognition, Technology & Work - The exploitation of so-called insiders is increasingly recognised as a common vector for cyberattacks. Emerging work in this area has considered the phenomenon...  相似文献   
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983.
Non-radiative cell membrane associated Förster Resonance Energy Transfer (FRET) from an enhanced cyan fluorescent protein (ECFP) to an enhanced yellow fluorescent protein (EYFP) is used for detection of apoptosis in 3-dimensional cell cultures. FRET is visualized in multi-cellular tumor spheroids by light sheet based fluorescence microscopy in combination with microspectral analysis and fluorescence lifetime imaging (FLIM). Upon application of staurosporine and to some extent after treatment with phorbol-12-myristate-13-acetate (PMA), a specific activator of protein kinase c, the caspase-3 sensitive peptide linker DEVD is cleaved. This results in a reduction of acceptor (EYFP) fluorescence as well as a prolongation of the fluorescence lifetime of the donor (ECFP). Fluorescence spectra and lifetimes may, therefore, be used for monitoring of apoptosis in a realistic 3-dimensional system, while light sheet based microscopy appears appropriate for 3D imaging at low light exposure.  相似文献   
984.
The liver is an organ with impressive regenerative potential and has been shown to heal sizable portions after their removal. However, certain diseases can overstimulate its potential to self-heal and cause excessive cellular matrix and collagen buildup. Decompensation of liver fibrosis leads to cirrhosis, a buildup of fibrotic ECM that impedes the liver’s ability to efficiently exchange fluid. This review summarizes the complex immunological activities in different liver diseases, and how failure to maintain liver homeostasis leads to progressive fibrotic tissue development. We also discuss a variety of pathologies that lead to liver cirrhosis, such as alcoholic liver disease and chronic hepatitis B virus (HBV). Mesenchymal stem cells are widely studied for their potential in tissue replacement and engineering. Herein, we discuss the potential of MSCs to regulate immune response and alter the disease state. Substantial efforts have been performed in preclinical animal testing, showing promising results following inhibition of host immunity. Finally, we outline the current state of clinical trials with mesenchymal stem cells and other cellular and non-cellular therapies as they relate to the detection and treatment of liver cirrhosis.  相似文献   
985.
Realistic mobility dynamics and underlying PHY/MAC layer implementation affect real deployment of routing protocols in vehicular ad hoc network (VANET). Currently, dedicated short range communication devices are using wireless access in vehicular environment (WAVE) mode of operation, but now IEEE is standardizing 802.11p WAVE. This work presents an in-depth simulation-based analysis of two reactive routing protocols, i.e., dynamic source routing (DSR) and ad hoc on-demand distance vector (AODV) with modified IEEE 802.11a PHY/MAC layers (comparable to 802.11p) in modified VANET mobility models (freeway, stop sign, and traffic sign) in terms of load, throughput, delay, number of hops, and retransmission attempts. Results obtained using OPNET simulator show that in urban/highway mobility scenarios, AODV??s performance with forthcoming 802.11p at high bit rate would be better than DSR in terms of high throughput, less delay, and retransmission attempts. Moreover, this comprehensive evaluation will assist to address challenges associated with future deployment of routing protocols integrated upon devices with upcoming IEEE 802.11p, concerning specific macro-/micro-mobility scenarios.  相似文献   
986.
The oviduct provides the environment to support gamete maturation, fertilisation and early embryo development. As there is a high incidence of early embryonic death in lactating dairy cows, this study compared expression of IGF family members in the oviduct between lactating Holstein-Friesian dairy cows (n=16, 81±2.4 days in milk) and nulliparous heifers (n=16, age 1.6±0.07 years) at three stages of the oestrous cycle: A) newly selected dominant follicle in the luteal phase, B) follicular phase before the LH surge and C) pre-ovulatory phase after the LH surge. Expression of IGF1, IGF2, IGF binding protein 2 (IGFBP2), IGFBP3 and IGFBP6 mRNA was determined in the ampulla of the oviduct. Oviduct side (ipsilateral or contralateral) with respect to the dominant follicle did not affect gene expression. Expression of IGF1 and all three IGFBPs increased significantly between the luteal and the pre-ovulatory phases, with no further significant alteration post-LH surge. Concentrations of circulating IGF1 were higher in heifers than in cows, as was the mRNA expression of IGF1, IGFBP3 and IGFBP6. The pre-LH surge rise in IGFBP2 mRNA was only observed in heifers. IGF2 expression was not influenced by either age or stage of cycle. These three IGFBPs are generally considered to inhibit IGF action. These results indicate tight regulation of IGF bioavailability in the oviductal environment around oestrus, with pronounced differences between cows and heifers, which are likely to influence early embryonic development. Further studies are required to assess the implications for embryo survival.  相似文献   
987.
Innovations in in vitro ovarian follicle culture have revolutionized the field of fertility preservation, but the successful culturing of isolated primary and small secondary follicles remains difficult. Herein, we describe a revised 3D culture system that uses a feeder layer of ovarian stromal cells to support early follicle development. This culture system allows significantly improved primary and early secondary follicle growth and survival. The stromal cells, consisting mostly of thecal cells and ovarian macrophages, recapitulate the in vivo conditions of these small follicles and increase the production of androgens and cytokines missing from stromal cell-free culture conditions. These results demonstrate that small follicles have a stage-specific reliance on the ovarian environment, and that growth and survival can be improved in vitro through a milieu created by pre-pubertal ovarian stromal cell co-culture.  相似文献   
988.
Currently, the determination of health risks to pesticide applicators from dermal exposure to these chemicals is assessed using either a concentrate of the compound or a relevant aqueous dilution. Neither of these conditions reflects a normal exposure of an individual when re-entering an area after pesticide application, that is, contact with dried residue of the diluted product on foliage. Methodology has therefore been developed to determine a relevant estimate of this potential dermal re-entry exposure from pesticide residues. Potential delivery platforms have been characterized for the transfer of pesticide residue to skin. Spin coating has been used to deposit uniform pesticide layers on to each platform. Five pesticides have been chosen to encompass a wide range of physicochemical properties: atrazine, 2,4-dichlorophenoxyacetic acid (2,4-D), chlorpyrifos, monocrotophos, and acetochlor. In vitro (Franz diffusion cell) experiments have been performed to monitor the transfer of these pesticides from the delivery platforms onto and through excised porcine skin. Parallel experiments were also conducted with aqueous pesticide dilutions for comparison, and a final in vivo measurement using ibuprofen (as a model compound) complemented the in vitro data. The results demonstrate that transfer of chemical residue onto and subsequently through the skin is dependent on the physical attributes of the residue formed. Thus, assessing dermal exposure to pesticides based on skin contact with either the chemical concentrate or a relevant aqueous dilution may incorrectly estimate the risk for re-entry scenarios.  相似文献   
989.
990.
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